[PATCH 2/5] net: cadence: macb: add EEE LPI statistics counters

[Nicolai Buchwitz <nb@tipi-net.de>]

Expose the GEM MAC's EEE Low Power Idle hardware counters through
ethtool -S:

- rx_lpi_transitions: number of RX LPI entry events
- rx_lpi_time: cumulative time spent in RX LPI
- tx_lpi_transitions: number of TX LPI entry events (TXLPIEN 0->1)
- tx_lpi_time: cumulative time in TX LPI

These are clear-on-read hardware registers at offsets 0x270-0x27c,
automatically collected by the existing gem_statistics read loop.

Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>
---
 drivers/net/ethernet/cadence/macb.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 729751d424c2..e3520e5aec67 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -1050,6 +1050,10 @@ struct gem_stats {
 	u64	rx_ip_header_checksum_errors;
 	u64	rx_tcp_checksum_errors;
 	u64	rx_udp_checksum_errors;
+	u64	rx_lpi_transitions;
+	u64	rx_lpi_time;
+	u64	tx_lpi_transitions;
+	u64	tx_lpi_time;
 };
 
 /* Describes the name and offset of an individual statistic register, as
@@ -1149,6 +1153,10 @@ static const struct gem_statistic gem_statistics[] = {
 			    GEM_BIT(NDS_RXERR)),
 	GEM_STAT_TITLE_BITS(RXUDPCCNT, "rx_udp_checksum_errors",
 			    GEM_BIT(NDS_RXERR)),
+	GEM_STAT_TITLE(RXLPI, "rx_lpi_transitions"),
+	GEM_STAT_TITLE(RXLPITIME, "rx_lpi_time"),
+	GEM_STAT_TITLE(TXLPI, "tx_lpi_transitions"),
+	GEM_STAT_TITLE(TXLPITIME, "tx_lpi_time"),
 };
 
 #define GEM_STATS_LEN ARRAY_SIZE(gem_statistics)
-- 
2.51.0